*doublelizes the disagreement.*
Comic character breasts are out of proportion compared to real life for a reason, because comic anatomy overal is out of proportion, even if comic is realistically drawn. I assume that the size of breast is adjusted to the size of the head and that's why, even if artist isn't a big-rack-freak, they are slightly bigger than in nature. Though, that doesn't justify all those artists you just named.

I saw a comic once where the lady-hero's butt cheeks were as huge, round and plump as her boobs. Whenever she bent over, it was hard to tell if it was a perspective shot from above where her head was leaned back.